Ethyl lactate synthesis in organic media using a magnetic supported CALB

NICOLÁS, PAULA; LASSALLE, VERÓNICA L.; FERREIRA, MARÍA LUJÁN

ENZYME AND MICROBIAL TECHNOLOGY

ELSEVIER SCIENCE INC

Año: 2025 vol. 191

0141-0229

The growing demand for sustainable chemical processes has spurred interest in enzymatic synthesis, particularlyfor valuable compounds like ethyl lactate. Traditional chemical methods often suffer from drawbacks, highlightingthe potential of enzymatic catalysis using immobilized lipases. This study evaluated the performance ofmagnetic biocatalyst, prepared by immobilizing Candida antarctica lipase B (CALB) on magnetic nanoparticles,for the batch synthesis of ethyl lactate in hexane. Initial experiments using free CALB and commercial Novozym435proved problematic due to enzyme denaturation and support instability, respectively. While titrationbasedmethods for monitoring the reaction were found to be unreliable due to lactic acid’s complex behaviorin the reaction medium, titratable acidity reduction suggested an optimal lactic acid to ethanol molar ratio of 1/10. Subsequent HPLC analysis revealed that the magnetic biocatalyst maintained a consistent conversion (%) athigher lactic acid concentrations (up to 17 mg/mL at 45◦C, with conversion above 60 % in 5 h), demonstrating itspotential for processing larger amounts of substrate. The initial reaction rate was estimated to be 3.8 mM/h. Thestudy also identified experimental challenges in accurate lactic acid quantification and potential catalystdegradation. In conclusion, the magnetic CALB biocatalyst shows promising activity and stability for ethyl lactatesynthesis, especially at higher substrate loads, paving the way for further optimization and application in sustainableproduction.